Executing nested aggregations

This kind of aggregation allows executing analytics on nested documents. When working with complex structures, the nested objects are very common.

Getting ready

You need an up-and-running Elasticsearch installation, as we described in the Downloading and installing Elasticsearch recipe in Chapter 2, Downloading and Setup.

To execute curl via the command line, you need to install curl for your operative system.

To correctly execute the following command, you need an index populated with the script (chapter_08/populate_aggregations.sh) available in the online code.

How to do it...

For executing nested aggregations, we will perform the following steps:

1. We must index documents with a nested type, as discussed in the Managing nested objects recipe in Chapter 3, Managing Mappings:

           { 
               "product" : { 
                   "properties" : { 
                       "resellers" : { 
                           "type" : "nested" 
                   ...